Topic: Do all hyper caps have a rear pickup pattern or just the MK41?

[su6oxone]

I've read a bunch of old threads re: that rear lobe pickup pattern on the MK41 hyper caps, but I'm not clear from the threads I read if this is specific for MK41s or if they are on other hyper caps too.  And if they are specific for MK41s, why would they be designed like that? 

[page]

Thats a general trait.

[boojum]

Mic patterns:

[su6oxone]

So that pesky rear lobe is a universal trait present in all hypercardioid pattern capsules... too bad, seems like a big drawback.  Ah well...

Thanks for the clarification guys. 

[Roger Gustavsson]

This drawback gets even more pronounced if you go for a shotgun microphone.
http://www.neumann.com/zoom.php?zoomimg=./assets/diagrams/s180_diagrams.htm&zoomlabel=Diagram&w=878&h=278
Click at the KM183, KM184 and KM185 at the bottom of the page and you get the picture.

Roger

[John Willett]

So that pesky rear lobe is a universal trait present in all hypercardioid pattern capsules...

There are basically only two patterns:
Omni - which is a pure pressure microphone (listens to *changes* in pressure)
Fig.8 - which is a pure pressure-gradient microphone (listens to *differences* in pressure)

Cardioid - this is like wiring and omni and fig.8 in parallel.

Super-cardioid - this is like wiring an omni and two fig-8s together - the rear lobe is the remnents of the second fig.8.

[DSatz]

What John Willett said. (Except, don't go wiring your microphones in parallel.)

The rear lobe isn't necessarily "pesky," however. I think it's a great advantage. Reflected sound that hasn't traveled much farther than the direct sound only confuses and jumbles a recording. Reflected sound that has traveled far and been spread out and had its edges honed off is what you want. In a more or less normally shaped recording venue, especially if your microphones are raised up and angled downward at least a little, the rear lobe gives you a greater proportion of reverberation from the farthest reaches of the room (and thus delayed by distance and both diffused and warmed/darkened by reflection) rather than from the area around the performers. That's all good.

In a well-made microphone, the rear lobe will have a "neat" pattern across the audio frequency range. The sound that it does pick up will be basically neutral, not emphasizing any one frequency range over the others. Again this is not necessarily the case for microphones with broader patterns. Dual-diaphragm cardioids, for example, typically have "bathtub-shaped" response around the back of the capsule, emphasizing the lows and highs (i.e. the "cardioid" pattern is maintained only in the midrange).

P.S.: The MK 41 is somewhat closer to being a supercardioid than a hypercardioid; Schoeps changed the designation in their catalogs many years ago. The "hypercardioids" of other manufacturers, including Sennheiser, Neumann, AKG and Beyer, are almost without exception the same way. A true hypercardioid would have even MORE of a rear lobe than a (near-)supercardioid, since it is closer to being a figure-8.

How to tell: Look for the "null" (the angle of lowest sensitivity) in the polar diagram. A figure-8 has its null 90° off axis; a true hypercardioid would have its null not so far from there at around 110°. A true supercardioid would have the null at about 126°, while most available "hypercardioid" microphones and capsules are in the zone around 120°. From the experience of the users of these microphones, that just seems to be the most useful place to plant one's flag.

P.P.S.: Just to clarify Roger G's reference above, the diagram for the Neumann KM 185 is another example of a microphone that's between supercardioid and hypercardioid, but a little closer to the supercardioid. "Shotgun" isn't a pattern--it's a type of microphone construction that takes a directional capsule of some given pattern and puts a slotted interference tube in front of it so that sound pickup from the sides is more or less canceled or attenuated above a certain frequency.

To compare the KM 185's pattern with that of a shotgun microphone, on the same Web site look at the "short shotgun" model KMR 81, or for an even more extreme example, the "long shotgun" model KMR 82. Keep in mind that these are some of the best examples of the type, and that the curves (especially the polar response curves at high frequencies) are smoothed and "idealized" ...

[su6oxone]

Thanks for the input gentlemen!  Always awesome to get your expert opinions. 

DSatz, you mentioned that the rear lobe could be a good thing especially if your mics are raised an angled downwards.  Would that be for situations where the speakers are positioned low and your mics are high (to avoid crowd noise)?  Just wondering what kinds of situations you would angle the mics downwards, as opposed to just having the mics pointing straight ahead at a similar elevation as the speakers. 

The rear lobe isn't necessarily "pesky," however. I think it's a great advantage. Reflected sound that hasn't traveled much farther than the direct sound only confuses and jumbles a recording. Reflected sound that has traveled far and been spread out and had its edges honed off is what you want. In a more or less normally shaped recording venue, especially if your microphones are raised up and angled downward at least a little, the rear lobe gives you a greater proportion of reverberation from the farthest reaches of the room (and thus delayed by distance and both diffused and warmed/darkened by reflection) rather than from the area around the performers. That's all good.

[stevetoney]

^ If I can jump in here, I think the idea is that the music is coming from the front (regardless of speaker positioning...low or high) and there's nothing behind the mics that's desirable to hear except what's reflecting from the rear walls, which comes from up high since people are usually milling around low.  Since there's usually no desirable sound coming from the rearward low direction (just chatting audience members), this positioning minimizes the audience from being picked up by the rear lobe.   

FWIW, the conclusion I reach for Mr. Satz's suggestion is that it's probably a good idea to angle mics slightly downward whenever using hypers or superhypers at a live show.

[su6oxone]

FWIW, the conclusion I reach for Mr. Satz's suggestion is that it's probably a good idea to angle mics slightly downward whenever using hypers or superhypers at a live show.

Thanks, that does makes logical sense to me.    Is this essentially the reasoning behind angling the mics downwards (that is, not dependent on the speaker elevation)? 

[stevetoney]

FWIW, the conclusion I reach for Mr. Satz's suggestion is that it's probably a good idea to angle mics slightly downward whenever using hypers or superhypers at a live show.

Thanks, that does makes logical sense to me.    Is this essentially the reasoning behind angling the mics downwards (that is, not dependent on the speaker elevation)? 

My thoughts are that a major part of the issue with understanding mic positioning is that, here in TS.com, it seems that there's a majority of people that think that the most important thing is the directional positioning of each of the two microphones relative to the sound source. 

I propose that this is not necessarily true.  It all depends on what your goal is with the recording. 

To take a ridiculous example, if the left speaker is on the ceiling and the right speaker is on the floor, many on TS.com would point their left microphone up and the right microphone down and claim that would provide the best sound for the recording.

In fact, if your goal is to recreate the sound that was experienced in the room at the time of the performance (including maintaining stereo imaging), it seems that it's AT LEAST as important how the two mics are positioned relative to each other. 

[datbrad]

In my own personal experience over the years running CK63s, I have found that keeping them exactly parallel to the floor, regardless of stand height, seems to work best for me as a general rule. I have never once heard anything negative that I can say is specifically due to the small rear lobe. YMMV

[SmokinJoe]

I've never quite understood this obsession with the rear lobe.  Yes, it's there, but it's typically down 10db or more with respect to the front.  I prefer to think more about the things off at 90* which are only down 3-6db depending on the pattern.

[John Willett]

P.S.: The MK 41 is somewhat closer to being a supercardioid than a hypercardioid; Schoeps changed the designation in their catalogs many years ago. The "hypercardioids" of other manufacturers, including Sennheiser, Neumann, AKG and Beyer, are almost without exception the same way. A true hypercardioid would have even MORE of a rear lobe than a (near-)supercardioid, since it is closer to being a figure-8.

I have never actually seen a hyper-cardioid from Sennheiser.

The Sennheiser super-cardioid is actually part way between the classic super-cardioid and hyper-cardioid.  It has been optimised so that the null point is 120° and the attenuation at 90° is equal to that at 180° = 10dB.

[BayTaynt3d]

I've never quite understood this obsession with the rear lobe.  Yes, it's there, but it's typically down 10db or more with respect to the front. 

QFT.

When I go hypers, it's almost always b/c I'm much more worried about other non-ideal, non-sweet spot conditions than I'm worried about the rear lobe.